Easily the service I hold the most disdain for on the 'net.
And users, indeed trust them. It's merchants that have the most reason to complain.
A mix of heavy financial regulation, and low competition, itself largely the result of the massive barrier to entry created by financial regulation.
Google Wallet also works.
There are are probably local debit-card based payment processors available to you as well; iDeal is one such system that is very popular in the Netherlands, it lets you pay with any Dutch debit account just as easily as with PayPal. It's a system in that there are a bunch of companies offering access to it. AFAIK processing costs are around ~€0.10, irrespective of transaction size at least for transactions under €1000.
It's a considerably smoother user flow than using a credit card, and it's just as fast. I think you'll be surprised and impressed.
Then, there is the problem with "buy $5 worth of bitcoin". Last time I checked, this was everything but trivial, at least here in Europe.
And finally, the last purchase I made with bitcoins on steam took more than 12 hours to get validated. I used the standard bitcoin fee of the bitcoin-qt client but it seems to be far from enough nowadays.
So you know what the problem is, but you pretend that it's not your problem. If you use any modern bitcoin wallet, android or not, it'll automatically append a reasonable fee, and validate in about 2 seconds.