Mastering and recording engineers DO NOT categorically cut off low frequencies, not for guitars, vocals or any other instruments. There are occasions where the recording environment may have sub-sonic noise that must be reduced, like recording an orchestra in a hall with a subway train running below, but the filtering involved is situation specific.
Location sound recording for film often dictates low frequency cut, and it's often applied during the recording to prevent low frequency overload of the recoding system. In that case, a cut below 150Hz is not uncommon, but again, it's situational. And often just not done. A good example would be in episodic TV and sitcoms. I've heard subsonic noise come and go, shot by shot, in 30 Rock, which is largely shot on a soundstage. My subwoofer reproduces it faithfully, its distracting, and should have been cut off in post, but they clearly didn't mix on a system with extended bass, so they missed it.
The reasons for low frequency cut fall into the categories of noise control or artistic choice, but noise control is the most likely. The goal is to remove the offending noise as much as possible without touching the desired signal, and its done with state-variable filters that can be custom tuned both in cut frequency and roll-off slope. There are also active noise reduction methods, both analog and DSP based, which can be tuned to isolate the noise without damage to the desired signal.
Excessive sub-sonic noise can cause problems in playback. For example, sub-sonic record rumble (vinyl) can cause woofer cones to wiggle enough that they induce a doppler frequency shift in mid band frequencies. Rolling off record rumble below 20Hz solves the problem.