[zephyrblows]

S(s) + 2e? ? S2?.-0.48
S(s) + 2H+ + 2e? ? H2S(g).+0.14

Does it mean that the oxidizing power of S(s) is stronger in acidic solutions?

[DevaDevil]

this mainly tells you that H₂S (g) is more stable than S^2-.
so indeed if protons are available sulfur will be less inclined to stay in its solid form than when no protons are available.

"oxidising power" is a strong term here, as both halfreaction potentials indicate neither of them is a strong oxidiser