You can read more at [1] - in short, critics of the new gTLDs would argue that:

1. It doesn't deliver the claimed increase the supply of domain names, as no-one would build a business or brand on whatever.info without securing whatever.com

2. It does shake down domain registrants for cash - if you already own whatever.com you'd better get whatever.info and whatever.sucks before someone else squats them.

3. These factors mean .info domains and suchlike are a stereotype of sketchy sites, which is a negative feedback loop.

[1] https://en.wikipedia.org/w/index.php?title=ICANN&oldid=93014...