What is a non-gendered synonym for "macho"?

In computer world, it seems like hardcore programmer is used in this sense and "Real programmer" phenomenon is compared to No true Scotsman fallacy. [However, hardcore programmer might be used in other senses as well.]

The term Real Programmer in computer folklore has come to describe the archetypical "hardcore" programmer who eschews the modern languages and tools of the day in favour of more direct and efficient solutions—closer to the hardware. The alleged defining features of a "Real Programmer" are extremely subjective, differing with time and place, in the fashion of the "no true Scotsman" fallacy. [Wikipedia]

Definition of "real programmer" from "The New Hacker's Dictionary" by Eric S. Raymond:

Real Programmer: [indirectly, from the book "Real Men Don't Eat Quiche"] n. A particular sub-variety of hacker: one possessed of a flippant attitude toward complexity that is arrogant even when justified by experience. The archetypal `Real Programmer' likes to program on the bare metal and is very good at same, remembers the binary opcodes for every machine he has ever programmed, thinks that HLLs are sissy, and uses a debugger to edit his code because full-screen editors are for wimps.

Related Dilbert comic strip:

Related readings:

• _{http://ronrecord.com/Mel.html}
• _{http://blog.enfranchisedmind.com/2009/04/return-of-the-real-programmer/}

It might be diverging from your context but:

In plain English, you can consider curt to emphasize a way of speaking that’s brief and blunt. It also has an added sense of being rude or rudely short.

A very similar word is brusque which can also be more general and describe the behavior.

curt: rudely brief or abrupt, as in speech or manner [TFD]

brusque: talking or behaving in a very direct, brief, and unfriendly way [MW]

An example of gender-politics situation from Price Waterhouse v. Hopkins case (on the issue of employer liability for sex discrimination):

The Gender Line: Men, Women, and the Law By Nancy Levit

In the particular context you give here, it’s not really about strength, but more about doing things in the most basic, unaided, original way possible. Considering we’re talking about developing computer code, this no-tech-help-allowed approach might properly be called oxymoronic, but a better term would, I think, be old-school (also written old-skool for humorous Internet effect):

: typical of an earlier style or form : based on a way of doing things that was common in the past
: using or supporting traditional practices
(Merriam-Webster)

A positive appellation referring to when things weren't flashy but empty of substance, were done by hard work, didn't pander to the lowest common denominator, and required real skill. Labour-saving devices, shortcuts that reduce quality and quitting before the task is done are not characteristics of "old school."
(Urban Dictionary)

This basic ‘feel’ of something can then be combined with some of the other suggestions already given here; the people in your comic strips can be described as competitively old-school or superciliously old-school, for example.

Or if a noun is what you’re after, competitive/supercilious old-schooler works very well, too. Unlike old-school itself, which has shades of meanings that are not relevant here (as in the M-W quotes above), old-schooler to my knowledge has only the meaning relevant to the UD quote above.

I think I would suggest that these individuals are demonstrating one-upmanship, or are perhaps purists or pedants.

One-upmanship is the art or practice of successively outdoing a competitor [...] the systematic and conscious practice of "creative intimidation", making one's associates feel inferior and thereby gaining the status of being "one-up" on them [...] Wikipedia

A pedant is a person who is excessively concerned with formalism, accuracy, and precision, or who makes an ostentatious and arrogant show of learning. Wikipedia

A purist is one who desires that an item remain true to its essence and free from adulterating or diluting influences. [...] According to the Merriam-Webster Online Dictionary, the term dates from 1706 and is defined as "a person who adheres strictly and often excessively to a tradition" [...] Wikipedia