Unfortunately, there is no control over what type of jack a recorder manufacturer uses. Mass built units, most likely the least expensive jack that fits their design.
...ahh save million dollars, we use cheap jack so product work when we ship then it fail they buy another!!!
Building consumer electronics is of course a balancing act between size, feature set, competitive products, cost, warranty, etc. Product designers DO have control over what parts are used and spend quite a bit of time trying to optimize the parts based on the balancing act mentioned. "Least Expensive" is almost always NOT the choice that is made, especially by makers with a brand to protect (ala Sony). The least expensive choices are NOT worth the hassles in production, product returns, and damage to the brand. If the maker is offering a warranty, (most reputable brands we deal with do), then the life of the jack is supposed to exceed the warranty time.
If cheapest cost was always the deciding factor it would extend to the XLR jacks used by these same makers and the argument that everyone should just use recorders with XLRs would lead to the same issues.
Taking a look at the products offered by Sony, Roland, etc and even the lower volume guys like Church and Niant shows products that offer 3.5mm jacks as an option for some of the connections. They seem to be comfortable with the tradeoffs involved with using these jacks. There are plenty of other threads on this board that discuss the plusses and minuses of 3.5mm TRS jacks. There are arguments for and against ANY connector type. I'm pretty sure every Walkman from the 1980's up to today’s MP3/FLAC players all use 3.5mm jacks for at least the headphone jack with success. There will always be failures in the field, but the 3.5mm jack is not evil
in and of itself. YMMV.
-MIQ