Trendy? Maybe. Wise? Not really, unless it's concerning a low percentage of your salary that you would otherwise put aside in your savings account.
I think that's the idea at this point, similar to rolling a small portion of your salary into a retirement account. For example,
GMO (the Japanese internet conglomerate) is rolling out their options this way:
Employees will have a lower limit of 10,000 yen (around $88) and an upper limit 100,000 yen ($882) for the bitcoin portion of their monthly salaries, and will also receive a bonus of 10 percent of the chosen amount as a "incentive," according to the firm.
Taking a rough estimation of Japanese wages across a corporate firm, I would guess this 10,000-100,000 yen limit is something like 1-10% of monthly wages, depending on the position. Personally, it's a bit upsetting that I've had money locked in my employer retirement account for so long with no access to Bitcoin investment options. I hope we see 401k options next year.