Why DELL PowerConnect and Juniper are so rare ? Why do enterprises stick with Cisco? [closed]

I have a little question, I'm actually studing IT in France, and when looking on alternative on the very [...] very expensive Cisco equipments, I've found Juniper and DELL PowerConnect pretty attractive on features and price, but I rarely see something else than the classics Cisco/LinkSys, HP Procurve and Netgear..

Why it's so rare to find those switch ? They looks really great but... I've never seen any Juniper or Powerconnect...

Why do enterprises stick with the expensive Cisco ?

I've tried to find how to buy both, it's quite easy with PowerConnect, everything is on the DELL website, but it looks it's very hard to find Juniper equipments in France :(

Thank you !

EDIt: For those who don't know JunOS, here is a video: http://www.exiletv.com/Podcast/videos/junos1.mov , It's really Amazing !

'everyone' knows cisco... it's [probably] easier to find consultant who has ccna/similar than one who has experience with junos, dell and all other extreme networks/foundry, etc.

i don't have traumatic experience form work with powerconnect - does the trick for me. and when it comes to juniper [but routers, not switches] - well, they carry quite a portion of internet traffic - i'd dare to say that they have bigger market share in carriers' core than cisco [or maybe huawei has already eaten most of the cake?]

No one ever got fired for buying Cisco.