I agree with you re IFE
However, re the seats, most, if not ALL LCC have "Leather" seats intalled. The reason being durability. May cost a small amount extra to install, however, the ongoing costs of cleaning/wear in minimal.. ie: a drunk footy play spews all over 3 seats, then they get wiped down and go off again in 2 minutes. If that happens with fabric, well, its a different story.
They are in most cases not full cowhide leather, they are in fact a synthetic leather. In the vehicles I use, they call it "Unnatural Leather" which is as durable as leather, has been manufactured to have similar properties, however, its half the price. Also note that usually the main contact areas are of this material, most backs/sides are actually a vinyl type blend.
Not being gross, but next time you are on a reaonably new one, sniff the seat(The upper part, because I may have been in it before you got there and that would not be nice), it wont have the strong leather smell, of say a nice italian leather lounge, also check out the structure and firmness of the "Leather"
Not taking a shot at the seats, because I actually quite like them, except those 738s with the coughpy old blue seats, they look really sad. That being said, they are 8 or so years old now, and original covers, so that tells you how long they last, even if they look cough.