It is quite strange to see England as favorites (after such an unconvincing game), but it so happens that in one part of the tournament bracket there are England and the Netherlands, and in the other Germany, Spain, Portugal and France.
It is obvious that England's path to the final will be much easier than the rest.
Your opinion is quite justified, England is the favorite because they have an easier path, they will only face Switzerland, then have the opportunity to face Netherlands or Turkey, the rest is only in the final. It's no surprise the bookies have made England favorites so far.
BTW, when I looked at the odds, I found that to get at least 1.8 odds, bettors on England would just have to go to -0.25 (handicap bet), this is the same as when Switzerland faced Italy, is it possible for England to have the same end as Italy? any answer?